I'm new to coin errors and I am wondering if this is a die break. If it is, does it give it any additional value?
That's definitely a plating issue. Though it's a unique one, it wouldn't really add any value. You might find someone who would give you a buck or two for it if they happen to collect oddities.
That's my take. Die breaks are usually thin lines which eventually fill in (called CUDS) if they continue to be used. This looks more like subsurface corrosion on older coins or Zinc bubbles on the post 1982 Lincolns.